The lone voice of horticultural reason
“Deadheading lilacs increases next year’s bloom”
Not a bad idea, not a waste of time, but then, not a shred of truth to the statement, either.
No one can find evidence that deadheading lilacs increases bloom for next year. Still, you read it in magazine articles and in a few detail-oriented gardening books.
Oh, it helps the plant, particularly when young, because deadheading the bloom circumvents the seed-production process. The plant will move into root-growing mode a few months early, never a bad thing in the north. But increase blooming the following year? The University of Minnesota can find no proof.
Continue to deadhead lilacs if you like the way it cleans them up in June. But when it gets to the point where you need to get the stepladder out and spend an hour or two on one bush, your time is probably better spent doing the gutters.
The Renegade Gardener